1. Field of the Invention
The present invention relates to an image recording system having a function of receiving image information and a function of performing preprogrammed recording of the received image information onto a plurality of recording media, and a method for controlling the image recording system.
2. Description of the Related Art
Recently, in the broadcasting industry, a shift toward digital broadcasting has been accelerated, and high quality images and high quality sounds are aimed. For these reasons, the amount of image information in broadcasting reaches approximately several tens of Mbps in information rate. As specifications required of an apparatus capable of recording this image, it is necessary that the information recording rate be higher than the broadcast information rate and the apparatus have a recording capacity of approximately several tens of GB (gigabyte) to realize recording for a considerable period of time. Examples of recording apparatuses capable of meeting these requirements include magnetic tape recording apparatuses, magnetic disk recording apparatuses (hard disk apparatuses) and optical disk recording apparatuses. Of these, magnetic tape recording apparatuses are poor in information accessing capability, and therefore, hard disk apparatuses and optical disk apparatuses are attracting attention as the next recording apparatuses. Particularly, hard disk apparatuses that have a sufficiently high recording rate and can have a sufficiently large recording capacity are sufficiently ready for recording of the above-mentioned high-quality broadcasts. Moreover, optical disk apparatuses capable of recording on exchangeable media although inferior to hard disk apparatuses in both recording rate and capacity are regarded as optimum as image storing apparatuses.
When these circumstances are considered, for example, a usage is considered such that a hard disk apparatus is used as a general-purpose image recording apparatus and when the user wants to store some of the recorded images, the images are stored on a medium by an optical disk apparatus. It is to be noted that another hard disk apparatus or a magnetic tape recording apparatus may be used as the means for storing images. Moreover, these apparatuses all have a preprogrammed recording function, and by enabling a target image to be recorded even during the user's absence by preprogramming the apparatus to record the target image, the image can be reproduced and viewed at the user's convenience. Thus, the preprogrammed recording function is one of the functions essential to these recording apparatuses.
When a larger amount of image information than the available space of the recording medium set in the image recording apparatus is recorded, the following occur:
(1) The user does not notice that the available space of the recording medium is smaller than the amount of the image information to be recorded, and the image information is interrupted when all the available space is used.
(2) The user takes out the recording medium with a small available space, and sets another recording medium with a sufficient available space in the apparatus. As means for solving these problems, the following technologies are proposed:
A multi-volume continuous recording apparatus disclosed in Japanese Unexamined Patent Publication JP-A 6-251562 (1994) has a buffer temporarily storing signals recorded on the recording medium, and by stopping the output of the buffer when the available space of the recording medium becomes small, resuming the output of the buffer after a different recording medium is set and performing recording, a long-time image can be recorded without the information interrupted when the recording medium is changed.
According to the information storage control method disclosed in Japanese Unexamined Patent Publication JP-A 10-172237 (1998), by stopping writing of data onto an external storage medium when it is determined that the data is not stored on the external storage medium and storing the data in internal storage means, the data scheduled to be stored can be stored without interrupted.
In a network recording control apparatus disclosed in Japanese Unexamined Patent Publication JP-A 11-176082 (1999), a data transmitter detects the remaining space of the recording medium of a data receiver forming a network, and by changing the receiver in the middle of data transmission when long-time image data is transmitted, data can be continuously recorded on a plurality of receivers.
As described above, image information larger than the available space of a recording medium is enabled to be recorded without interrupted by continuously recording the information on another recording medium or apparatus. This operation is performed by user himself or by an apparatus.
As described above, when a larger amount of image information than the available space of the recording medium set in the recording apparatus is recorded, the image can be recorded only to the middle or changing the recording medium places a load on the user. In the technologies disclosed in the patent applications, since one piece of image information is recorded being divided on two or more media, the management of recording media with respect to image information is complicated, and to seamlessly reproduce an image without any interruption at the points of division and without the same part of the image repeated, a recording and reproduction processing of the joints of the points of division of the information is required. This complicates the system and increases the price.